Since my post a few days ago I have decided against the Alside Excalibur, and was leaning towards the softlite Imperial. Found a dealer here in NoVa who carries Softlite, Shuco, and Simonton, so I'm going to his shop tomorrow to see full sizes of all three, which I hope will be better than one tiny sample at my dining room table. I've researched what to look for in terms of u/SHG/air leakage for this area -- and will be looking at corners, fit at the meeting rails, look and feel, etc. Any other advice for what to look for to make a good call? Also, should I be wary of installers who use so many different windows, or it that normal?